AIR CONDITIONER

摘要

A rotational speed Cr of a compressor 21 during a defrosting operation is controlled within a control range that corresponds to a capacity ratio P, a total sum Pi of rated capacity of an indoor unit, or a refrigerant pipe length Lr. Accordingly, even in the case where a refrigerant circulation amount during the defrosting operation is reduced due to an installation state of an air conditioner 1, it is possible to prevent suction pressure from being significantly reduced and falling below a performance lower limit value of the compressor 21. Thus, damage to the compressor 21 can be prevented. In addition, it is possible to prevent a case where the suction pressure falls below the performance lower limit value of the compressor 21 and thus low-pressure protection control is executed. Therefore, a case where the restoration of the heating operation is delayed does not occur.

主权项

1. An air conditioner comprising:
at least one outdoor unit having a compressor, a flow passage switching unit, an outdoor heat exchanger, a low-pressure detector, and an outdoor unit controller; at least one indoor unit having an indoor heat exchanger; and at least one liquid pipe and at least one gas pipe for coupling the outdoor unit and the indoor unit, wherein the low-pressure detector detects suction pressure that is pressure of a refrigerant suctioned into the compressor, the outdoor unit controller controls a rotational speed of the compressor at a time that a defrosting operation is performed within a predetermined rotational speed control range in accordance with the suction pressure received from the low-pressure detector, and the rotational speed control range is defined in accordance with a capacity ratio that is a value obtained by dividing a total sum of rated capacity of the indoor unit by a total sum of rated capacity of the outdoor unit.